Method and device for preventing slip of work piece
AssigneeJtekt Corporation
InventorAkira Makiuchi
Life of this patent
Estimating the term…
Abstract
A master servo motor and a slave servo motor that synchronously drive for rotation a master main spindle provided with a center that supports one end of a work piece and a slave main spindle provided with a center that supports the other end of the work piece are included. Before grinding, a slip detection cycle that detects a limit current value for the servo motors, at which the work piece and the centers slip, is executed and, during grinding, a grinding condition is changed to prevent a slip between the work piece and the centers in advance at the time when any one of current values of the servo motors has reached a slip threshold value set on the basis of the limit current value.
Claims12
A method for preventing a slip of a work piece in a grinding machine that includes:
- a master main spindle provided with a center that supports one end of the work piece;
- a slave main spindle provided with a center that supports the other end of the work piece;
- and a master servo motor and a slave servo motor that synchronously drive the master main spindle and the slave main spindle for rotation, wherein at least one of the center provided for the master main spindle and the center provided for the slave main spindle is pressed toward the other one of the centers to generate friction forces between the work piece and the centers to thereby synchronously drive both ends of the work piece for rotation, and, in this state, a wheel head is caused to cut into the work piece to grind the work piece, comprising:
- before grinding, executing a slip detection cycle that detects a limit current value for the servo motors, at which the work piece and the centers slip, and
- during grinding, when any one of current values of the servo motors has reached a slip threshold value computed on the basis of the limit current value, changing a grinding condition to prevent a slip between the work piece and the centers in advance.
A method for preventing a slip of a work piece in a grinding machine that includes:
- a master main spindle provided with a center that supports one end of the work piece;
- a slave main spindle provided with a center that supports the other end of the work piece;
- and a master servo motor and a slave servo motor that synchronously drive the master main spindle and the slave main spindle for rotation, wherein at least one of the center provided for the master main spindle and the center provided for the slave main spindle is pressed toward the other one of the centers to generate friction forces between the work piece and the centers to thereby synchronously drive both ends of the work piece for rotation, and, in this state, a wheel head is caused to cut into the work piece to grind the work piece, comprising:
- setting a prescribed current value in advance;
- and
- in a repeating production cycle, executing a simplified cycle that proceeds to a grinding cycle when the prescribed current value is reached at the time when at least one of the master main spindle and the slave main spindle is rotated by the servo motors in a state where the work piece is supported between the master main spindle and the slave main spindle.
A grinding machine that includes a master main spindle provided with a center that supports one end of the work piece;
- a slave main spindle provided with a center that supports the other end of the work piece;
- and a master servo motor and a slave servo motor that synchronously drive the master main spindle and the slave main spindle for rotation, wherein the center provided for the slave main spindle is pressed toward the center provided for the master main spindle to generate friction forces between the work piece and the centers to thereby synchronously drive both ends of the work piece for rotation and, in this state, a wheel head is caused to cut into the work piece to grind the work piece, comprising:
- detecting means for, before grinding, detecting a limit current value for the servo motors, at which the work piece and the centers slip;
- computing means for computing a slip threshold value on the basis of the limit current value;
- storage means for storing the slip threshold value computed by the computing means;
- and
- grinding condition changing means for, during grinding, changing a grinding condition such that the work piece and the centers do not slip at the time when any one of current values of the servo motors has reached the slip threshold value.
Dependencies are inferred from the claim text.